Abstract: A clearing saw comprises a circular saw blade which is rotatable relative to a portable frame and whose periphery is at least partly exposed to permit sawing and cutting through a tree-trunk. With the frame of the saw there is associated at least one arm which is pivotal on a joint and provided at its free end with an abutment member located outside the periphery of the saw blade and adapted, when desired, to be applied against another tree-trunk adjacent the trunk to be cut, in order during cutting of the first trunk to positively maintain the saw blade at a distance from said other trunk.

Abstract: A device in pressure medium operated needle hammers, the needles (24) being arranged in a reciprocatingly movable working member (3) by at least one flexible holder member (31, 39) and, by a friction grip of the holder member being caused to follow the movements of the working member, but being permitted an axial play within predetermined limits through overcoming the frictional resistance. In addition, the rear portions of the needles can be arranged in a sealed chamber (34) filled with a hydraulic medium (35).

Abstract: A bow saw having a frame and a saw blade which is tightened between the opposite ends of the frame when used. The frame is composed of three individual elements which are interconnected by means of simple and cheap connections and which are firmly held together as long as a tensile stress is maintained in the blade by means of screw members. These elements are collapsible in order to reduce the size of the saw. To this end a main element has a cavity for housing the blade, while two end elements have cavities allowing the main element to be partially introduced therein.

Abstract: A fluid pressure operated impact mechanism of the type having a reciprocating working member guided for movement along an axis toward and away from a stop member, a pressure chamber between the working and stop members to receive a fluid pressure medium to exert forces separating the two members, and pressure sealing means for maintaining the pressure chamber sealed as the working member and stop member separate. The mechanism is characterized by a sealing arrangement which requires few precision parts yet is applicable to a variety of different devices. In the sealing arrangement, the pressure chamber is formed in the surface of at least one of the members, so that the two members meet along a separating line at the periphery of the pressure chamber. One of the members forms a support wall or flange extending in an axial direction along the separating line, and a flexible sealing means extends from the support wall of the one member to the other member, thereby effecting a seal therebetween.